Natural products are a rapidly expanding field of study. There is increased concern by skilled artisans over the use and consumption of fossil-fuel based compounds. As a result, new ways to utilize renewable products are being examined in order to lower the environmental burden on the planet. 1,4:3,6-dianhydrohexitols are considered biomass-derived substances, in that they are obtained from natural products. 1,4:3,6-dianhydrohexitols are important starting materials and intermediates in various organic synthetic reaction schemes such as in the formation of numerous pharmaceutical compounds, in food production, cosmetic production, plastic and polymer production. One such class of derivatives of 1,4:3,6-dianhydrohexitols are ether derivatives. Ether derivatives of 1,4:3,6-dianhydrohexitols, such as isosorbide dinitrate, are useful as a medication to relieve the pain of angina attacks and to reduce the frequency of such attacks by improving blood flow to the heart. For example, U.S. Pat. No. 4,976,965 discloses a medicinal composition comprising a mixture of isosorbide nitrates and dihydropyridines, and an alkylene glycol ether.
Another important derivative is dimethyl isosorbide, which is useful as industrial solvents and pharmaceutical additives, as well as for use in personal care products. The structure of dimethyl isosorbide is shown below:

Dianhydrosugar ethers are prepared by reacting alkyl halides and dialkylsulfates with an anhydrosugar such as isosorbide and isomannide, a 1,4:3,6-dianhydrohexitol, in the presence of a base or phase transfer catalysts such as tetra-n-butylammonium bromide, benzyltriethyammonium bromide or N-methyl-N,N-dioctyloctan-1-aminium chloride. However, these processes require a highly pure anhydrosugar starting material in order to achieve reasonable yields at to be cost effective.
There is a need for a simple and cost effective process for the production of very pure anhydrosugar ethers, at reasonable yields, without having to use pure anhydrosugar alcohols as the starting materials.